Field
Embodiments of the present invention generally relate to a method and apparatus for fabricating devices on a semiconductor substrate. More particularly, embodiments of the present invention provide an apparatus for transferring substrates and confining a processing environment in a chamber.
Description of the Related Art
During manufacturing of semiconductor devices, a substrate is usually processed in a processing chamber, where deposition, etching, and thermal processing may be performed to the substrate. Improving process uniformity and reducing particle contamination are two constant goals for semiconductor processing, especially as dimensions of semiconductor devices rapidly reduce.
A semiconductor processing chamber generally includes a chamber body defining an inner volume for processing a substrate. A substrate support is usually disposed in the inner volume to support the substrate during processing. One or more slit valve doors may be formed through the chamber body to allow passage of the substrate into and out of the inner volume. Gas supply paths and pumping channels are also formed through the chamber body to provide processing gas and pump the inner volume to a desired pressure. The slit valve opening, the gas supply paths, the pumping channels, and the substrate support usually cause the inner wall of the chamber body to be asymmetrical and/or irregular, thus causing non-uniform conductance and/or electric field asymmetries. As a result, different areas on the substrate may be exposed to different processing conditions and uniformity of processing across the substrate decreases. Furthermore, the processing gas may travel to the slit valve area and cause contamination around the slit valve area.
Therefore, there is a need for methods and apparatus for improving process uniformity and reducing contamination in a semiconductor processing chamber.